Image forming apparatus capable of outputting color and monochrome images, control method thereof and computer readable recording medium

1. An image forming apparatus, comprising: an image output unit outputting a color image and a monochrome image; an accepting part accepting an image data; a processor performing RIP convert on the image data accepted by said accepting part, to provide data for output image; a first determining unit determining whether said data for output image corresponds to a color image or a monochrome image; a feature extracting unit extracting feature of said data for output image; a reference storage storing a determination reference related to said feature, as to whether a color image is to be output by said image output unit; a second determining unit determining, if it is determined by said first determining unit that said data for output image corresponds to a color image, whether said feature satisfies the determination reference related to said feature; and an output controller controlling said image output unit such that a color image corresponding to said data for output image is output, on condition that said second determining unit determines that the determination reference related to said feature is satisfied.

2. The image forming apparatus according to claim 1 , wherein a developing unit develops the image data accepted by said accepting part to bit map image data; said feature extracting unit extracts amount of color data of said bit map image data as said feature; and said reference storage stores, as the determination reference related to said feature, the amount of color data of said bit map image, or ratio of the amount of color data with respect to total amount of data on an output sheet of paper.

3. The image forming apparatus according to claim 1 , further comprising a status data extracting unit extracting status data, which is related to a status of said image output unit; wherein said reference storage further stores determination reference related to said status data as to whether a color image is to be output by said image output unit; said second determining unit determines, on condition that said determination reference related to said feature is satisfied, whether said status data satisfies said determination reference related to said status data or not; and said output controller controls said image output unit such that a color image corresponding to said data for output image is output, on condition that said second determining unit determines that the determination reference related to said status data is satisfied.

4. The image forming apparatus according to claim 3 , wherein said image output unit outputs an image by supplying toner or ink; said status data extracting unit extracts, as said status data, remaining amount of toner or ink supplied by said image output unit; and said reference storage stores, as said determination reference related to said status data, a reference of remaining amount or consumption ratio from the fully charged status of the image forming apparatus, of toner or ink supplied by said image output unit.

5. The image forming apparatus according to claim 3 , wherein said image output unit includes a photoreceptor; said status extracting unit extracts, as said status data, an amount of use of said photoreceptor; and said reference storage stores, as the determination reference of said status data, a reference of the amount of use of said photoreceptor or a ratio of the amount of use of said photoreceptor with respect to a predetermined amount of use of the photoreceptor.

6. The image forming apparatus according to claim 3 , wherein said status data extracting unit extracts, as said status data, history of color image output of said image output unit; and said reference storage stores, as said determination reference related to said status data, a reference to the history of color image output of said image output unit.

7. The image forming apparatus according to claim 6 , wherein said status data extracting unit extracts, as said status data, number of print jobs that provided color image outputs of said image output unit; and said reference storage stores, as said determination reference related to said status data, a reference to the number of jobs that provided color image outputs of said image output unit.

8. The image forming apparatus according to claim 1 , wherein said accepting part further accepts data of printing conditions related to said image data; said reference storage further stores a determination reference related to said printing condition data as to whether a color image is to be output by said image output unit; said second determining unit determines, on condition that said determination reference related to said feature is satisfied, whether said printing condition data satisfies said determination reference related to said printing condition data or not; and said output controller controls said image output unit such that a color image corresponding to said data for output image is output, on condition that said second determining unit determines that the determination reference related to said printing condition data is satisfied.

9. The image forming apparatus according to claim 8 , wherein said reference storage stores, as said determination reference related to printing conditions, a reference of number of copies in the printing conditions related to said image data; and said second determining unit determines whether the number of copies in said printing conditions satisfies said determination reference related to said printing condition data.

10. The image forming apparatus according to claim 8 , wherein said reference storage stores, as said determination reference related to printing conditions, a reference of number of prints in the printing conditions related to said image data; and said second determining unit determines whether the number of prints in said printing conditions satisfies said determination reference related to said printing condition data.

11. The image forming apparatus according to claim 8 , wherein said reference storage stores, as said determination reference related to printing conditions, a reference of printing paper size in the printing conditions related to said image data; and said second determining unit determines whether the printing paper size in said printing conditions satisfies said determination reference related to said printing condition data.

12. The image forming apparatus according to claim 1 , wherein said output controller controls said image output unit such that said data for output image is output as a monochrome image, when the result of determination by said second determining unit is not to let said image output unit output a color image corresponding to said data for output image.

13. The image forming apparatus according to claim 1 , further comprising an accepting part accepting an input of information from outside; wherein said output controller controls said image output unit such that said data for output image is output as a color image, on condition that said accepting part has accepted an input of specific information, when the result of determination by said second determining unit is not to let said image output unit output a color image corresponding to said data for output image.

14. The image forming apparatus according to claim 1 , wherein said output controller controls said image output unit such that said data for output image is not output, when the result of determination by said second determining unit is not to let said image output unit output a color image corresponding to said data for output image.

15. A method of controlling an image forming apparatus outputting a color image and a monochrome image, comprising the steps of: accepting image data; RIP converting said accepted image data to obtain data for output image; determining whether said data for output image corresponds to a color image or a monochrome image; extracting feature of said data for output image; reading a determination reference related to said feature as to whether a color image is to be output or not; determining, when said data for output image is determined to correspond to a color image, whether said feature satisfies said determination reference related to the feature or not; and outputting a color image corresponding to said data for output image, on condition that said feature satisfies said determination reference related to the feature.

16. A computer readable recording medium, recording a program causing an image forming apparatus, outputting a color image and a monochrome image and accepting image data, to execute the steps of: determining whether data for output image obtained by RIP convert of said accepted data corresponds to a color image or a monochrome image; extracting feature of said data for output image; reading a determination reference related to the feature as to whether a color image is to be output or not; determining, when said data for output image is determined to correspond to a color image, whether said feature satisfies said determination reference related to the feature or not; and outputting a color image corresponding to said data for output image, on condition that said feature satisfies said determination reference related to the feature.

17. The recording medium according to claim 16 , wherein at said step of reading said determination reference, a reference related to ratio of color data amount with respect to black data amount is read; at said step of extracting the feature, the color data amount and the black data amount in said data for output image are extracted; and at said step of determining whether said determination reference is satisfied or not, whether the ratio of the color data amount with respect to the black data amount satisfies said reference related to the ratio or not is determined.

18. The recording medium according to claim 16 , wherein at said step of reading said determination reference, a reference related to color data amount is read; at said step of extracting the feature, the color data amount in said data for output image is extracted; and at said step of determining whether said determination reference is satisfied or not, whether the color data amount in said data for output image satisfies said reference related to the color data amount or not is determined.

19. The recording medium according to claim 16 , wherein at said step of reading said determination reference, a reference related to a ratio of color data amount with respect to overall data amount of said data for output image is read; at said step of extracting the feature, the color data amount and black data amount in said data for output image are extracted; and at said step of determining whether said determination reference is satisfied or not, whether the ratio of color data amount with respect to the entire data amount of said data for output image satisfies said reference related to the ratio or not is determined.

20. A computer readable recording medium, recording a program causing an image forming apparatus, outputting a color image and a monochrome image and accepting image data, to execute the steps of: RIP converting said accepted image data to obtain data for output image; determining whether said data for output image corresponds to a color image or a monochrome image; extracting position in a document and color information corresponding to said data for output image; storing a determination reference related to a position of color image in the document, as to whether a color image or a monochrome image is to be output; and determining, based on said determination reference, whether said data for output image is to be output as a color image or a monochrome image.

21. An image forming apparatus, comprising: an image output unit capable of outputting a color image and a monochrome image; an accepting part accepting a job for output, including image data; an extracting unit extracting, based on said job for output and a status of said image output unit, data for comparison related to at least one of these; a reference storing unit for storing a determination reference corresponding to said extracted data for comparison as to whether a color image is to be output from said image output unit or not; a determining unit determining whether said image data corresponds to a color image or a monochrome image, and if it is determined to correspond to a color image, determining whether said data for comparison satisfies said determination reference or not; and an output controller controlling said image output unit such that a color image corresponding to data for output image generated based on said image data is output, on condition that said determining unit determines that said determination reference is satisfied.

22. The image forming apparatus according to claim 21 , wherein said data for comparison is any of remaining amount of toner charged in said image output unit, an amount of use of a photoreceptor used at said image output unit, and history of color output by said image output unit.

23. The image forming apparatus according to claim 22 , wherein said history of color output is number of jobs that provided color outputs.

24. The image forming apparatus according to claim 21 , wherein said data for comparison is printing condition included in a job for output.

25. The image forming apparatus according to claim 24 , wherein the printing condition is any of number of copies, number of prints, and printing paper size.

26. A method of controlling an image forming apparatus including an image output unit capable of outputting a color image and a monochrome image, comprising the steps of: accepting a job for output including image data; extracting, based on said job for output and a status of said image output unit, data for comparison related to at least one of these; reading a determination reference corresponding to said extracted data for comparison as to whether a color image is to be output from said image output unit or not; determining whether said image data corresponds to a color image or a monochrome image, and if it is determined to correspond to a color image, determining whether said data for comparison satisfies said determination reference or not; and causing said image output unit to output a color image corresponding to data for output image generated based on said image data is output, on condition that said determination reference is determined to be satisfied.

27. A computer readable medium storing a program, to be executed by an image forming apparatus accepting a job for output including image data and including an image output unit capable of outputting a color image and a monochrome image, for performing the steps of: extracting, based on said job for output and a status of said image output unit, data for comparison related to at least one of these; reading a determination reference corresponding to said extracted data for comparison as to whether a color image is to be output from said image output unit or not; determining whether said image data corresponds to a color image or a monochrome image, and if it is determined to correspond to a color image, determining whether said data for comparison satisfies said determination reference or not; and permitting said image output unit to output a color image corresponding to data for output image generated based on said image data, on condition that said determination reference is determined to be satisfied.